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Parameter scaling

Mika Bay
Intellectual 600 points

Has TI given any document to give scaling factors of the various ACTUAL motor/drive parameters like motor current, motor speed, motor inductance, resistance etc. with 32bit value represented inside dsp? 

  • 0
    TI__Guru** 119680 points
    Mika,
    I'm not sure exactly what you are asking for. Can you please clarify?

    you want to understand for example what the hex value of a speed_krpm would be in the register?

    these variables are all managed in IQmath format, most of them in IQ24, which means 1 sign bit, 7 integer bits, and 24 fractional bits.
  • 0 in reply to ChrisClearman
    Intellectual 600 points

    For serial transmission of data, I wanted to check if all parameters can be fitted in 16bit, so amount of data transfer will reduce, so I was trying to see - how these parameters are defined so that I can find a best way to fit them in 16bits. Unfortunately, they all do not seem to be in IQ24 format, (For example, terminal voltage & speed do not seem to be in IQ24 format). So I wanted to know if TI has  any document defining the same...

  • 0 in reply to Mika Bay
    TI__Guru** 119680 points
    everything we pull out into gMotorVars is either a decimal/float or IQ24.
    If you are talking about the data in the ADC, that is a 16b value.

    but the 28x is a word based architecture, so you probably need 32-bit for most variables